Olympus 5050 noise and file size test
 
 
 

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Here you will find the results of a test in which image noise in homogeneous colour areas is measured at different ISO and internal sharpening settings. The test is performed both with an Olympus C5050Z and an Olympus C2000Z digital camera (the C2000 for comparison).
There are also graphs showing how file size changes at different ISO and internal sharpening settings.
For questions or comments send me an email.
 
 

Conclusions


 
 

Test procedure

I prepared two scenes containing objects with smooth, non-reflective surfaces with homogeneous colour and no texture.
 


Scene 1: glass table 
(the white sheet of paper is the back side of a photo)

Scene 2: a Ricola sweets box
(macro shot without flash)

To measure the noise I chose areas with no texture and homogeneous colour. I didn't measure the noise in image areas containing detail (would be very complicated, if possible at all - you'd have to subtract each image area from the corresponding image area of a noiseless image).
 


Scene 1

Scene 2

In a noiseless image, the standard deviation in an area of homogeneous colour should be zero. Therefore, the higher the standard deviation, the bigger the noise.

I took a total of 44 shots for each scene (ISO 64, 100, 200 and 400; sharpening levels -5 .. +5) with shutter priority, i.e. exposure time was fixed and the camera would choose the aperture to properly expose the image.

I also took three shots (ISO 100, 200 and 400) with an Olympus C2000 digital camera (2MP at 1600x1200) to compare the noise levels (for the C2000 images the size of the noise measurement area was approx. 50x50 pixels). The C2000 has bigger pixels (4x4 micrometer vs. 2.8x2.8 for the C5050), therefore noise should be lower.

With the histogram function I measured the standard deviation in the noise measurement areas of each image. The results are shown in the graphs below.
 
 
 

Scene 1

Exposure data
Olympus C-5050Z
  • Shutter priority at 1/30S
  • F3.2 - 6.3 depending on ISO
  • 13.2mm focal length
  • Auto white balance
  • No flash
  • SHQ JPEG 2560x1920
  • daylight illumination
Olympus C-2000Z
  • Shutter priority at 1/30S
  • F2.5 - 5.0 depending on ISO
  • 12mm focal length
  • Auto white balance
  • No flash
  • SHQ JPEG 1600x1200
  • daylight illumination


Scene 1 with the noise measurement area (resized to 640x480)
 
 


Noise measurement area in full size
 
 


Scene 1 test results - Noise vs. ISO and sharpening level

Comments


 

Scene 2

Exposure data
Olympus C-5050Z
  • Shutter priority at 1/50S
  • F3.6 - 7.0 depending on ISO
  • macro shot at 21mm focal length
  • Auto white balance
  • No flash
  • SHQ JPEG 2560x1920
  • incandescent lamp illumination
Olympus C-2000Z
  • Shutter priority at 1/50S
  • F2.8 - 5.0 depending on ISO
  • macro shot at 19mm focal length
  • Auto white balance
  • No flash
  • SHQ JPEG 1600x1200
  • incandescent lamp illumination


Scene 2 with the noise measurement area (resized to 640x480)
 
 


Noise measurement area in full size
 
 


Scene 2 test results - Noise vs. ISO and sharpening level

Comments


 

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© Copyright 2003 Alfred Molon